Why the most popular rule of weight loss is completely wrong | Hacker News Reader

Why the most popular rule of weight loss is completely wrong

washingtonpost.com

9 pointsdlo11 comments

The headline is misleading and clickbait-y.

The rule in question (3500 calories deficit results in one pound of weight loss) is mostly true, even if oversimplified. The fact that your metabolism drops as your weight drops just means that the calorie/day input needs to drop correspondingly to maintain the same deficit.

As the article states, the fact that the weight loss isn't entirely fat is a minor error. Thus, the 3500 calorie guideline is maintained, as long as you remember that it is a deficit and not a static amount.

This is correct. As your weight continues to drop you should recalculate your TDEE and reduce your food intake accordingly. Likewise if you are trying to gain weight.

Which is why people have the most success with a combination of diet and weight loss. As you lose weight, your metabolism drops, but as you exercise (and in particular when you do strength training), your metabolism increases. If you have the discipline to keep your calorie intake under control as your metabolism increases, you will lose weight.

As it turns out, bro science was accidentally correct about something.

Not to mention that the article confounds calories, a physical unit of energy, Calories, a unit of nutritional energy, and kilojoules, the preferred physical unit of energy.

At one point, it indicates that 3,500 calories corresponds to a pound of body weight, then later indicates this came from research suggesting that 3,500 kJ corresponds to a pound of body weight and that this is where the 3,500 calories figure comes from.

Problem is, 3,500 kJ = 836 520.076 calories = 836.520076 Calories. So which is it? 3,500 kJ per pound of body weight, 3,500 Calories, or 837 Calories, or something else?

FYI: A nutritional Calorie is actually a kilocalorie (1,000 calories). One Calorie = 4.184 kJ.

According to the Hacker's Diet [1], 3.500 Calories is equivalent to a pound.

[1] Admittedly poor reference, but in tone with the Hacker News. Also, the author most probably sources from the same reference the article does for the traditional conversion and I trust him to not mess up with units.

Hmm, OK. Doesn't explain how the "3,500 kJ per pound" got in there - perhaps I still have optimistically high expectations, but I would have hoped that somewhere along the line the author or their editor would have noted that a pound cannot be equivalent to both 3.5 Mcal and 3.5 MJ. But mayhaps I wax pedantic.

You're right, I was also very surprised by this error and have commented on it as soon as this was posted. I just wanted to elucidate the correct value.

It is clickbait-y and it is a nothing article really.

The rule is just a rough guideline to FAT loss, little different than weight loss.

And like you said, the "plateau" effect doesn't negate the "rule", it only really reaffirms that fat loss will require that calorie deficit.

Wow, that is a blatant error in the very beginning of the article:

>> it was 3,500 kilojoules, otherwise known as calories

NO! Although calories and joules are indeed two measures of the same physical quantity (energy), there is a conversion factor of 4 between them: 1 calorie = 4.18400 joules.

As a side note, the usual nutritional calorie (or "Calorie", with uppercase 'C'), is actually 1000 calories, or 4184 Joules.

This doesn't inspire confidence in the rest of the article: "...and found that it was 3,500 kilojoules, otherwise known as calories."

http://www.google.com/search?q=3500+kilocalories+in+kilojoul...

Is this the most popular rule? I'd think that it's "eat below your TDEE".

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